Susanna Rustin hoped to become a councillor on Westminister city council in 2009. Photograph: Frank Baron for the Guardian

Three years ago I joined the Green party. Since then I have twice been a candidate in local council elections and next month I am on the ballot paper for the West Central seat on the London Assembly – the panel of 25 elected alongside the mayor whose job is to scrutinise him.

After May, who knows? I have no plans to give up the day job. I like being a journalist and, unlike politics, it pays me a salary. But then again, until I joined the Green party I had never dreamed of standing for anything.

I think more people should get involved in politics. I'm not cynical but I think most politicians are pretty bad, not as individuals so much as in their collusion with a dysfunctional system (just look at party funding). So this is my beginner's guide to getting involved: 10 easy steps to becoming a politician.

1 Join a political party

This is not compulsory. This year's mayoral contest features one independent and the Independent Network exists to offer support. But unless you are George Galloway, it is very hard to get elected without a big party machine behind you. Guardian columnist Suzanne Moore and climate activist Tamsin Omond both stood for parliament as independents in 2010, and neither got more than 300 votes. "The way politics is done, it is not really possible," says Moore. "Even things such as getting leaflets printed, put into boxes and taken to the post office, you need people to help. However loyal your friends are, it's a lot to ask. But I think putting an X against your own name is an experience everyone should have. It's fun. I started off trying to be as honest as I could, and within two weeks I found myself giving these faux-expert answers and turning into this awful political thing that I despise. It gave me a lot more sympathy with politicians. To me it was a gesture about puncturing the spectacle. I suppose I did it as an anarchist."

If you decide to take the conventional route, you will need to decide what your politics are, then work out which party offers the closest match. As for prices, Conservative membership costs £25, Labour £43, Green £31, Lib Dems £12, SNP £13. All have various special offers. And be warned: even before you have clicked "submit", they will ask for more.

2 Move house

This might sound silly, but unless you live in area where your party is in charge, getting elected is incredibly difficult. In Surrey, the last Labour MP was elected in 1945, while Scotland in 2012 has just one Conservative. If you find yourself in hostile territory, and unwilling to contemplate upheaval, you could set up a pressure group and try to influence things that way. Alternatively, you could commit to a life of opposition. Someone has got to do it, and you may find there is less infighting in a local party where so little power is at stake.

3 Consider the House of Lords

The average age of peers is 69 but the youngest members of the second house of parliament are in their 30s: Nat Wei, former big society tsar, and lawyer Elizabeth Berridge. You will need to be appointed, so you will need to join a party first (though if this is impossible you could become a crossbencher after a life of public service).

The huge advantage of the Lords is that you do not need to get elected, so no leafletting, no canvassing and no risk of humiliating defeat. What's more, and weird, the fact you are not elected doesn't seem to matter: Lord (Peter) Mandelson was business secretary after leaving the Commons, Baroness (Sayeeda) Warsi became a cabinet minister having been soundly beaten in Dewsbury, and Lord (Andrew) Adonis became secretary of state for transport despite never even standing for parliament.

Labour peer Bryony Worthington, who worked for Ed Miliband before he appointed her, says: "The Lords is a much more collegiate atmosphere, not quite so tense and adversarial. And it doesn't require you to give up your day job, so you keep a foot in the outside world. The people you work with are amazing and, surprisingly, it's quite family-friendly – they have never had a mum with a baby before but they have been very welcoming." Lib Dem peer Meral Hussain-Ece, a councillor for 16 years before being appointed two years ago, says the Lords "takes some getting used to – all the rules and customs that aren't written down. But it's a wonderful place to work, I won't make any bones about it. It's a huge privilege, the staff and attendants are so supportive, and the level of debate is second to none – far higher than anything you hear in the Commons."

4 Check you won't get fired

Some employers are funny about politics, especially if yours aren't the same as theirs, or they think you should spend all your time in the office. The Guardian doesn't mind my Green activities (they are viewed, I think, as a harmless hobby), but BBC journalists must seek the advice of the chief adviser politics before doing anything that could compromise impartiality.

Civil servants "must comply with any restrictions that have been laid down", which in practice depends how high up they are, while Britain's biggest employer, Tesco, told me politics is fine so long as it is "kept separate from our work duties and doesn't influence how we behave" (doesn't politics influence all behaviour?). If you work for a small business, or an opinionated one, it may be more a question of personalities.

5 Make a choice: No 10 or village hall

If you want to be prime minister chances are it's too late, though the next PM and the one after that must be out there somewhere. Parliament should not be out of reach, though it could be harder if you are much past 40 (the average age of 2010's new intake was 42 and a half).

Get selected now to fight a seat in the next general election (even if it's one you have no chance of winning), and build from there. The party will notice if you do well, even if you are defeated, and next time you could be on a shortlist for something winnable.

"I worked my socks off, and I was gutted," he says. "I went to every community meeting I could and talked to thousands of people, but unfortunately my Tory opponent had been selected three years before and in the end I lost by a few hundred votes. But I'm very bloody-minded, and determined to try again. Last year, Labour won back control of Warrington borough council and the momentum is definitely with us."

If your ambitions are more modest, becoming a local councillor should be fairly straightforward, provided you have some useful skills and are prepared to make an effort. All three parties admit to needing new talent (a recent Be a Councillor! event at the House of Commons was designed to attract new entrants). Outside big cities there are county, district and town or parish councils to choose from, the latter especially suitable if you don't want to join a party since half of England's parish councils (Scotland and Wales are different) aren't party-political at all.

6 Check your bank balance

Until you get elected, politics is unpaid. As a hobby it's very affordable (knocking on strangers' doors is free) but as soon as it starts encroaching on the working week (if you want to do anything with the local press, for example, who mostly don't work weekends) costs mount up. I spent £40 on my first local election campaign, which hopefully wouldn't put many people off, but to do the London Assembly is going to cost me at least £1,000, mainly because I have "bought" some time off work for campaigning (I'm keeping my annual leave for holidays) and some extra childcare. I am also contributing to my £1,000 deposit (which I'll get back if I win 5% of the vote), donating to the Green mayoral campaign, and I need to upgrade my crummy phone if I am to get any better at social media.

But this is peanuts compared with the cost of fighting a parliamentary election. Bent took four months off work to campaign in Warrington, and in any seat it believes to be winnable a constituency party will want the candidate to commit a similar period of time – which, of course, means money.

In many places you don't really need to campaign to get elected to local government. Most council seats, like most parliamentary ones, don't usually change hands, and in Westminster, where I live, the Conservatives could put more or less anyone on the ballot paper in Belgravia and still get them elected. On the other hand, the greater the likelihood of getting elected, the more competition there is. Decide whether you prefer to fight a campaign within your party, for selection to a safe seat, or take the fight to the other side.

In marginal seats, parties devote huge resources to collecting data and residents are courted intensively with personalised letters and information (Labour in 1997 devised a new science of targeting called Excalibur) and even in the friendliest territory it's essential to knock on some doors, go to meetings (residents' associations, single-issue campaigns, coffee mornings, the WI) and meet constituents, if only so you know what to expect once you have been elected.

But don't forget the issues: when Green party leader Caroline Lucas fought one of the stand-out campaigns of the last election to become Britain's first Green MP, she thanked thousands of supporters for their hard work but said the result showed voters care about social justice and the environment.

8 Be in the media

Learn to spot a story and write a press release. Attend community events and plan some actions and campaigns of your own: petitions, protests, talks. Write letters to the local papers and be in the news as often as you can.

You need to look tidy, at least to start with. There is plenty of election lore about the taller candidate, or the one with more hair or the less sweaty skin winning (Kennedy v Nixon in 1960 is the classic case) but fortunately for those of us without image consultants, this mainly applies to world leaders. I was grateful to the friend who told me not to wear green – a rosette is enough.

10 Change your name

Local parties, believe it or not, obsess over the alphabetical placement of candidates. It's better to be higher up the list, allegedly, so if your name is Rustin and you insist on keeping it, try to make sure you aren't competing against a Cameron.

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